Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06126 (CD1a)
 2,221 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Notch-mediated cellular interactions are known to regulate cell fate decisions in various developmental systems. A previous report indicated that monocytes express relatively high amounts of Notch-1 and Notch-2 and that the immobilized extracellular domain of the Notch ligand, Delta-1 (Delta(ext-myc)), induces apoptosis in peripheral blood monocytes cultured with macrophage colony-stimulating factor (M-CSF), but not granulocyte-macrophage CSF (GM-CSF). The present study determined the effect of Notch signaling on monocyte differentiation into macrophages and dendritic cells. Results showed that immobilized Delta(ext-myc) inhibited differentiation of monocytes into mature macrophages (CD1a+/-CD14+/- CD64+) with GM-CSF. However, Delta(ext-myc) permitted differentiation into immature dendritic cells (CD1a+CD14-CD64-) with GM-CSF and interleukin 4 (IL-4), and further differentiation into mature dendritic cells (CD1a+CD83+) with GM-CSF, IL-4, and tumor necrosis factor-alpha (TNF-alpha). Notch signaling affected the differentiation of CD1a-CD14+ macrophage/dendritic cell precursors derived in vitro from CD34+ cells. With GM-CSF and TNF-alpha, exposure to Delta(ext-myc) increased the proportion of precursors that differentiated into CD1a+CD14- dendritic cells (51% in the presence of Delta(ext-myc) versus 10% in control cultures), whereas a decreased proportion differentiated into CD1a-CD14+ macrophages (6% versus 65%). These data indicate a role for Notch signaling in regulating cell fate decisions by bipotent macrophage/dendritic precursors.
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PMID:The Notch ligand, Delta-1, inhibits the differentiation of monocytes into macrophages but permits their differentiation into dendritic cells. 1152 Jul 88

Dendritic cells (DC) with the potential to induce anti-tumour immunity represent one of the promising candidates for cancer vaccines. Efficiency of ex vivo DC generation depends on culture conditions, especially protein components in the plasma or serum used. Using human serum albumin (HSA), we devised a constant and reproducible culture method for DC generation from peripheral blood CD14+ cells. The number of DC obtained with 2% HSA-supplemented cultures containing granulocyte-macrophage colony-stimulating factor and interleukin 4 were consistently higher than in cultures with various concentrations of autologous plasma or serum. The concentrations and time points tested for plasma or serum considerably affected the number of DC recovered. DC prepared with HSA acquired the ability to uptake dextran, and expressed high levels of major histocompatibility (MHC) and co-stimulatory molecules similar to DC cultured with autologous plasma or serum. Although DC cultured with autologous plasma or serum consisted of CD1a+ and CD1a- populations, DC differentiated in the presence of HSA expressed CD1a. DC obtained with HSA primed and induced immunogenic peptide-specific cytotoxic T lymphocytes against a tumour rejection antigen, HER2. These findings suggest that our method for preparation of DC with HSA should prove valuable in DC generation for immunotherapy.
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PMID:Efficient ex vivo generation of dendritic cells from CD14+ blood monocytes in the presence of human serum albumin for use in clinical vaccine trials. 1155 98

Langerhans cells (LCs) represent a subset of immature dendritic cells (DCs) specifically localized in the epidermis and other mucosal epithelia. As surrounding keratinocytes can produce interleukin (IL)-15, a cytokine that utilizes IL-2Rgamma chain, we analyzed whether IL-15 could skew monocyte differentiation into LCs. Monocytes cultured for 6 d with granulocyte/macrophage colony-stimulating factor (GM-CSF) and IL-15 differentiate into CD1a(+)HLA-DR(+)CD14(-)DCs (IL15-DCs). Agents such as lipopolysaccharide (LPS), tumor necrosis factor (TNF)alpha, and CD40L induce maturation of IL15-DCs to CD83(+), DC-LAMP(+) cells. IL15-DCs are potent antigen-presenting cells able to induce the primary (mixed lymphocyte reaction [MLR]) and secondary (recall responses to flu-matrix peptide) immune responses. As opposed to cultures made with GM-CSF/IL-4 (IL4-DCs), a proportion of IL15-DCs expresses LC markers: E-Cadherin, Langerin, and CC chemokine receptor (CCR)6. Accordingly, IL15-DCs, but not IL4-DCs, migrate in response to macrophage inflammatory protein (MIP)-3alpha/CCL20. However, IL15-DCs cannot be qualified as "genuine" Langerhans cells because, despite the presence of the 43-kD Langerin, they do not express bona fide Birbeck granules. Thus, our results demonstrate a novel pathway in monocyte differentiation into dendritic cells.
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PMID:Interleukin 15 skews monocyte differentiation into dendritic cells with features of Langerhans cells. 1158 22

Macrophage inflammatory protein (MIP)-3alpha is a chemokine involved in the migration of T cells and immature dendritic cells. To study the contribution of proinflammatory cytokines and chemokines to the recruitment of these cells in rheumatoid arthritis (RA) synovium, we looked at the effects of the monocyte-derived cytokines IL-1beta and TNF-alpha and the T cell-derived cytokine IL-17 on MIP-3alpha production by RA synoviocytes. Addition of IL-1beta, IL-17, and TNF-alpha induced MIP-3alpha production in a dose-dependent manner. At optimal concentrations, IL-1beta (100 pg/ml) was much more potent than IL-17 (100 ng/ml) and TNF-alpha (100 ng/ml). When combined at lower concentrations, a synergistic effect was observed. Conversely, the anti-inflammatory cytokines IL-4 and IL-13 inhibited MIP-3alpha production by activated synoviocytes, but IL-10 had no effect. Synovium explants produced higher levels of MIP-3alpha in RA than osteoarthritis synovium. MIP-3alpha-producing cells were located in the lining layer and perivascular infiltrates in close association with CD1a immature dendritic cells. Addition of exogenous IL-17 or IL-1beta to synovium explants increased MIP-3alpha production. Conversely, specific soluble receptors for IL-1beta, IL-17, and TNF-alpha inhibited MIP-3alpha production to various degrees, but 95% inhibition was obtained only when the three receptors were combined. Similar optimal inhibition was also obtained with IL-4, but IL-13 and IL-10 were less active. These findings indicate that interactions between monocyte and Th1 cell-derived cytokines contribute to the recruitment of T cells and dendritic cells by enhancing the production of MIP-3alpha by synoviocytes. The inhibitory effect observed with cytokine-specific inhibitors and Th2 cytokines may have therapeutic applications.
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PMID:Enhancing effect of IL-1, IL-17, and TNF-alpha on macrophage inflammatory protein-3alpha production in rheumatoid arthritis: regulation by soluble receptors and Th2 cytokines. 1169 82

Experimental protocols for cancer immunotherapy include the utilization of autologous monocyte-derived dendritic cells (moDC) pulsed with tumor antigens. However, disease can alter the characteristics of monocyte precursors and some patients have increased numbers (up to 40%) of the minor CD16(+) monocyte subpopulation, which in healthy individuals represent 10% of blood monocytes. At the present, the capacity of CD16(+) monocytes to differentiate into DC has not been evaluated. Here, we investigated the ability of CD16(+) monocytes cultured with granulocyte- macrophage colony-stimulating factor, IL-4 and tumor necrosis factor-alpha to generate DC in vitro, and we compared them to DC derived from regular CD16(-) monocytes. Both monocyte subsets gave rise to cells with DC characteristics. They internalized soluble and particulate antigens similarly, and both were able to stimulate T cell proliferation in autologous and allogeneic cultures. Nevertheless, CD16(+) moDC expressed higher levels of CD86, CD11a and CD11c, and showed lower expression of CD1a and CD32 compared to CD16(-) moDC. Lipopolysaccharide-stimulated CD16(-) moDC expressed increased levels of IL-12 p40 mRNA and secreted greater amounts of IL-12 p70 than CD16(+) moDC, whereas levels of transforming growth factor-beta1 mRNA were higher on CD16(+) moDC. Moreover, CD4(+) T cells stimulated with CD16(+) moDC secreted increased amounts of IL-4 compared to those stimulated by CD16(-) moDC. These data demonstrate that both moDC are not equivalent, suggesting either that they reach different stages of maturation during the culture or that the starting monocytes belong to cell lineages with distinct differentiation capabilities.
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PMID:CD16+ and CD16- human blood monocyte subsets differentiate in vitro to dendritic cells with different abilities to stimulate CD4+ T cells. 1171 98

We tried to efficiently generate human dendritic cells (DCs) from CD34+ peripheral blood hematopoietic progenitor cells mobilized by high-dose chemotherapy and subsequent administration of granulocyte colony-stimulating factor, using a liquid suspension culture system. Among various combinations, the combination of c-kit ligand, flt-3 ligand, c-mpl ligand (TPO), and interleukin (IL)-4 most potently generated the number of CD1a+CD14- DCs in cultures containing granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF-alpha). The delayed addition of IL-4 on day 6 of culture gave rise to an additional increase in the yield of CD1a+CD14-DCs that were characterized by the expression of HLA-ABC, HLA-DR, CD80, CD86, and CD83. The majority of the sorted CD1a-CD14+ cells derived from 6-day culture of CD34+ cells gave rise to CD1a+CD14- DCs and CD1a-CD14+ macrophages on day 12 of culture in the presence and absence of IL-4, respectively. These findings suggest that IL-4 promotes the differentiation of CD1a- CD14+ cells derived from mobilized CD34+ peripheral blood hematopoietic progenitors to CD1a+ CD14- DCs. The majority of these DCs expressed CD68 but not the Langerhans-associated granule antigen, a finding that suggests they emerge through the monocyte differentiation pathway. The addition of TPO and IL-4 to cultures did not affect the potential of DCs to stimulate the primary allogeneic T-cell response. These findings demonstrated that the combination of c-kit ligand plus flt-3 ligand plus TPO with GM-CSF plus TNF-alpha, followed by IL-4, is useful for ex vivo generation of human DCs from mobilized CD34+ peripheral blood progenitors.
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PMID:Efficient ex vivo generation of human dendritic cells from mobilized CD34+ peripheral blood progenitors. 1172 65

Chemokines are mediators of innate and acquired immunity. CCL18, also designated pulmonary and activation-regulated chemokine (PARC), dendritic cell-derived CC chemokine-1 (DC-CK1), alternative macrophage activation-associated CC chemokine-1 (AMAC-1) and macrophage inflammatory protein-4 (MIP-4), was for the first time isolated from peripheral blood mononuclear cells (PBMC) and biochemically characterized. We found that CCL18/PARC protein is spontaneously secreted by PBMC and is selectively induced in PBMC by staphylococcal enterotoxins (SEA, SEB) and IL-4, but not by IFN-gamma and the CXCL8/IL-8 inducers lipopolysaccharide (LPS) or Concanavalin A. Human fibroblasts, chondrocytes and endothelial cells did not produce CCL18/PARC in response to inflammatory mediators such as measles virus, double-stranded RNA, LPS or IL-1beta, whereas up to 150 ng/ml of CCL2/MCP-1 was induced under these conditions. In synovial fluids from septic and rheumatoid arthritis patients, fourfold-enhanced CCL18/PARC levels (150 ng/ml) were detected compared to those in crystal-induced arthritis and osteoarthritis. In septic arthritis, the synovial levels of CCL18/PARC were fivefold higher than those of CXCL8/IL-8. Immunochemistry revealed CD68(+) monocytes/macrophages as the main CCL18/PARC-producing cell type in both PBMC and arthritic synovial tissue. In addition, CD1a(+) blood dendritic cells expressed CCL18/PARC. These findings suggest that monocytic cells respond to Gram-positive bacterial infection by the production of CCL18/PARC in the synovial cavity.
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PMID:Selective induction of CCL18/PARC by staphylococcal enterotoxins in mononuclear cells and enhanced levels in septic and rheumatoid arthritis. 1174 96

Dendritic cells (DCs) play important roles in initiation and regulation of immune responses. DCs derived from human monocytes can be classified according to presence of CD1a molecules. Although CD1a+ DCs can be prepared from monocytes in media containing GM-CSF, IL-4, and FCS, it has been reported that CD1a+ DCs could not be easily obtained from monocytes using media containing human serum or plasma. In this study, we demonstrate for the first time that heparin can reliably induce differentiation of CD1a+ DCs from monocytes with or without autologous serum or plasma. The development of CD1a+ DCs is heparin concentration dependent (0-50 U/ml). Comparing with CD1a- DCs developed without heparin, CD1a+ DCs express higher CD40 and CD80 and lower CD86. Both CD1a+ and CD1a- DCs express similar levels of HLA-DR. CD80, CD86, HLA-DR, and CD40 are proportionally up-regulated when both types of DCs are stimulated with LPS or LPS plus IFN-gamma. The effect of heparin is neutralized by heparin-binding proteins, such as protamine sulfate, platelet factor-4, and beta-thromboglobulin. Functionally, heparin-treated DCs respond to LPS or LPS plus IFN-gamma with higher IL-10 and less IL-12 production than heparin-untreated DCs. Heparin-treated DCs are more potent in priming allogeneic and autologous CD4+ T cells to proliferate and to produce both type 1 and type 2 cytokines. The results of our study show that CD1a+ DCs can be prepared from monocytes ex vivo without using xenogeneic serum and may be used for immunotherapy.
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PMID:Heparin induces differentiation of CD1a+ dendritic cells from monocytes: phenotypic and functional characterization. 1180 47

The object of this study is to explore a culture method to generate a large number of functional and mature dendritic cells (DC) from human CD34+ hematopoietic progenitor cells. In the present study, we used a two-step method combined with calcium ionophore to induce DC from cord blood (CB) or normal human bone marrow (BM) CD34+ progenitor cells. The two-step method consists of 10 days of first step culture for the expansion and proliferation of CD34+ hematopoietic progenitor cells in the presence of SCF, IL-3, IL-6, G-CSF, and 7--11 days of second step culture for the induction of DC in the presence of GM-CSF, IL-4 and TNF-alpha. By the two-step culture, total nucleated cells were increased 208+/-66 (+/-SD, n=13), or 94+/-29 (n=5)-fold in the culture of CB or BM cells, respectively, compared with the number of CD34+ cells at the time of starting culture. Out of the total nucleated cells, 23 +/-10.4% of cells in CB cell culture and 25 +/-5% of cells in the BM cell culture acquired DC characteristic phenotypes, which were marked expressions of CD1a, HLA-DR, co-stimulatory molecules such as CD80, CD40, and adhesion molecule such as CD58. In allogeneic mixed leukocyte reaction (MLR), two-step cultured cells showed potent allo-stimulatory capacity. With this two-step culture, the absolute number of CD1a+ cells that co-expressed HLA-DR, CD80, CD40 and CD58 was enhanced approximately 3 times in CB cell culture and 1.9 times in BM cell culture, compared with the commonly used one-step culture method for the generation of DC from CD34+ cells using SCF, GM-CSF and TNF-alpha. However, on these DC generated in the two-step culture, the expressions of co-stimulatory molecule CD86 and mature DC marker CD83 were not sufficient. By the treatment of two-step cultured cells with calcium ionophore agent (A23187), the expression of co-stimulatory molecules such as CD86 and CD80 (especially CD86) was up-regulated. Besides, the expression of mature DC marker CD83 was remarkably induced by treatment with A23187 for a short duration (24 h). Consistent with the up-regulation of surface molecules CD86, CD80 and CD83, the two-step cultured cells treated with A23187 also showed a stronger allo-stimulatory capacity compared with the cells without A23187 treatment. In conclusion, the present study demonstrated that the two-step culture method effectively improved the yield of CD1a+ DC generated from CD34+ cells, and the phenotypes and functions of these CD1a+ DC could be enhanced efficiently by treatment with a calcium ionophore agent.
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PMID:Generation of functional and mature dendritic cells from cord blood and bone marrow CD34+ cells by two-step culture combined with calcium ionophore treatment. 1186 Oct 65

Polycyclic aromatic hydrocarbons (PAHs) such as benzo(a)pyrene (BP) are environmental carcinogens exhibiting potent immunosuppressive properties. To determine the cellular bases of this immunotoxicity, we have studied the effects of PAHs on differentiation, maturation, and function of monocyte-derived dendritic cells (DC). Exposure to BP during monocyte differentiation into DC upon the action of GM-CSF and IL-4 markedly inhibited the up-regulation of markers found in DC such as CD1a, CD80, and CD40, without altering cell viability. Besides BP, PAHs such as dimethylbenz(a)anthracene and benzanthracene also strongly altered CD1a levels. Moreover, DC generated in the presence of BP displayed decreased endocytic activity. Features of LPS-mediated maturation of DC, such as CD83 up-regulation and IL-12 secretion, were also impaired in response to BP treatment. BP-exposed DC poorly stimulated T cell proliferation in mixed leukocyte reactions compared with their untreated counterparts. In contrast to BP, the halogenated arylhydrocarbon 2,3,7,8-tetrachlorodibenzo-p-dioxin, which shares some features with PAHs, including interaction with the arylhydrocarbon receptor, failed to phenotypically alter differentiation of monocytes into DC, suggesting that binding to the arylhydrocarbon receptor cannot mimic PAH effects on DC. Overall, these data demonstrate that exposure to PAHs inhibits in vitro functional differentiation and maturation of blood monocyte-derived DC. Such an effect may contribute to the immunotoxicity of these environmental contaminants due to the major role that DC play as potent APC in the development of the immune response.
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PMID:Polycyclic aromatic hydrocarbons affect functional differentiation and maturation of human monocyte-derived dendritic cells. 1188 29


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